We want to go back to terry moran who has been in the stadium all morning long, as so many have gathered to celebrate the life of nelson mandela. Terry? Reporter: George, as you and I have seen, this was a singular moment in history of our times, the unprecedented gathering of the world's most powerful people. But it was also an intensely personal event. Tens of thousands of the people you see behind me, braving a drenching, cold rain to be here. Each one of them to say good-bye to the man who gave them freedom and the world an unforgettable example. &#9834; this morning, the world came to south africa, braving the pouring rain to celebrate the man who changed history. We want to celebrate the life of the man who took the pain of millions of south africans. Reporter: It was the largest gathering of world leaders ever. Over 100 heads of state, joining nelson mandela's family and thousands of south africans. His struggle was your struggle. His triumph was your triumph. Your udignity and your hope found expression in his life. And your freedom, your democracy, is his cherished legacy. Reporter: Just as mandela brought his country together, his memorial began with a coming together of religions, during an interfaith prayer. He, too, transcended his personal pain and years of suffering, to forgive and to embrace his brothers and sisters, who inflicted so much pain on him. To madiba for his selfless efforts, salvaging the nation and leading it to the path of peace, reconciliation and harmony. Reporter: Then, a song to nelson mandela. &#9834; Nelson mandela &#9834; Reporter:3 of mandela's 18 grandchildren and 12 great-grandchildren, took the stage to honor their grandfather. The tree that towers above the rest, is broken by the wind. Child of the wind. Of the land. Child that dreams of a future where black and white, rich and poor, men, women and children, must live side-by-side, dreaming the same dream, realizing at the crucible of time in our land, we salute you. Nelson mandela's grandchildren there, terry. The tributes pouring in all morning long. You've seen, as you've said, so much joy, so much celebration today. And the crowd really embracing president obama when they saw him come up on the screen. Reporter: No question. His picture. And then, when he stepped forward to the podium, the crowd just lit up. And the crowd was in rapt attention to the president's words. There is a kinship between south africa and the united states, even though the western superpower, the african nation, there is nonetheless a similarity in the diversity and the challenges the diversity brings. And we listen to each other and can learn from each other. That is certainly the feeling here when president obama is speaking. We talked a little about the rain so far. As you mentioned earlier this morning, so many people happy in south africa to see that rain today. Reporter: It was a happy feeling. There's no question the people came here not to cry, not to grieve, to remember, with pride and joy and a unique sense of solidarity that extended right through everyone in this stadium, including us. People were friendly here. It was a beautiful feeling. And when we got the sense that within this stadium, the crucible of the south african experience, is the crucible of the human experience. A diversity of people coming together, to honor a man who showed a way forward.

This transcript has been automatically generated and may not be 100% accurate.

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